An important consideration in the design of light fixtures is selection of the light source. Fluorescent or incandescent lamps have long been the light source of choice in many light fixtures used in commercial applications. But fluorescent and incandescent lamps have drawbacks. For example, fluorescent lamps may result in undesirable lighting that is focused and intensely directed beneath the lamp but dark in areas peripheral to the lamp. Both fluorescent and incandescent lamps require a high level of energy, and thus, are more expensive to operate. Incandescent lamps burn out relatively quickly, which causes material waste. Fluorescent lamps contain mercury, a toxic substance. In general, fluorescent and incandescent lamps are not very “green” or environmentally friendly. Such lamps may also require increased operator time in changing out the lamp when it is burned out.
Another light source that is gaining in popularity is the light-emitting diode, or LED. LEDs might be desirable in certain applications because they generally require less power than fluorescent and incandescent lamps, and they also generate less waste. LEDs last longer, which may be desirable to users who operate the light fixture for long hours and could reduce the frequency of lamp replacements. Finally, LEDs do not contain any toxic mercury.
Despite the fact that it may not be desirable to use fluorescent or incandescent lamps, it may still be desirable to use at least part of the light fixture that was designed to house the fluorescent or incandescent lamp, as long as the special operating characteristics of LEDs are appropriately addressed. Manufacturing equipment and procedures that were used to make the existing enclosure can continue to be used to house the LED boards. Finally, re-using an existing enclosure preserves a consistent look in a room that may already be equipped with light fixtures. (Otherwise, the room may have some light fixtures with new enclosures and some with older ones that look different from one another.)
In general, it may be desirable to re-use at least some parts of a light fixture design (and in particular, an enclosure of a light fixture) to house an LED board or other light source. One problem arises, however, in managing the thermal energy that may be produced by LEDs. One way to manage thermal energy is to incorporate heat sinks into the light fixture. An existing fixture may not be provided with such heat sinks, however, and may not have room to incorporate such heat sinks. Managing the thermal energy may be particularly problematic if the enclosure of the light fixture is made of a material that is insulating, such as plastic, that traps the thermal energy inside the enclosure.
Another problem is that modifications to an existing enclosure may make the light fixture unsuitable for use in particular applications. For example, if the light fixture is to be used in an environment that may be exposed to water, such as a parking garage or other outdoor environment, then it may be desirable to provide a water-resistant light fixture. Modifying an existing enclosure may involve creating apertures in the enclosure, which may introduce water into the light fixture, damaging the components inside.
Thus, it is desirable to re-use parts of an existing light fixture, such as an enclosure, to house LED boards or other light sources.
It is also desirable to manage the thermal energy produced by such LEDs inside the enclosure, particularly if the enclosure is made of plastic.
Finally, if it is necessary to modify the design of an existing enclosure to house an LED board, then it may be desirable for such modifications to be water-resistant.